PROJECT SUMMARY Gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM) during pregnancy are rapidly rising in prevalence and both disproportionately burden minority women. The existing health disparities in diabetes mellitus (DM) prevalence and perinatal outcomes are substantial public health problems that are exacerbated by the obesity epidemic. Although effective intensive management and treatment can reduce the morbidity associated with perinatal DM, the self-management skills and engagement required to achieve optimal glycemic control during pregnancy are complex and burdensome, especially amount low-income, minority women. Prior data from our group and others have identified that the social, psychological, knowledge-based, resource-related, and logistical burdens of DM during pregnancy reduce women's ability to optimize glycemic control, which is directly related to adverse perinatal outcomes. Thus, we propose to draw upon existing evidence, a rigorous theoretical foundation, and our preliminary data regarding barriers to and facilitators of DM care during pregnancy to refine and test a health behavior tool to educate and support low-income, minority pregnant women with GDM and T2DM. Mobile health (mHealth) technology is a promising avenue for behavioral health interventions, and our tool, SweetMama, incorporates educational, motivational and supportive elements to positively impact maternal health behaviors without amplifying provider burdens. Our long-term hypothesis is that the use of an innovative and interactive mHealth tool can improve maternal and neonatal outcomes. To develop this tool and address this hypothesis, we propose two specific aims. First, we will develop an optimized version of SweetMama via a 2-step sequential process of in-depth usability testing. We will perform focus groups and individual usability testing with low-income, minority pregnant women with DM followed by refinement of SweetMama based on participant input. Usability testing will apply mixed methodology. Second, we will determine the acceptability, feasibility, and behavioral outcomes of SweetMama use via a pilot feasibility trial in which women who are randomized to use SweetMama will utilize the tool for the duration of pregnancy, and women in the control arm will receive usual care. Women will undergo interview and survey assessments of self-efficacy, knowledge, satisfaction and engagement of care. Health care providers will also be included in focus groups and interviews to offer perspectives on patient needs and SweetMama. Completion of this aim will critically address feasibility of a larger trial and will allow us to pilot procedures for a fully powered randomized controlled trial. This proposal will result in a refined, first-of-its kind, scalable mHealth intervention that has the potential to improve perinatal outcomes and reduce DM-related perinatal health disparities through the use of evidence-based and patient-centered techniques. The results from these groundbreaking studies will lay the foundation for future clinical investigations of SweetMama.